Printing press

ABSTRACT

Printing press improvements useful in flexographic printing. A register control device comprises first and second freely rotatable gears, separate clutches alternatively securing one or other of the gears to a drive and a bridging shaft having gears meshed with both free gears. With clutch associated with first free gear engaged, drive train from first gear to driven roll results; alternatively with that clutch disengaged and other engaged, drive train from second free gear, through bridge shaft to first free gear to driven roll results. One gear train produces 1 to 1 surface speed ratio between plate and impression rolls, the other produces a register correction speed, off e.g. by 0.5 percent. Also shown are drive shaft directly driving the impression roll with free gears coaxial and free thereon; first free gear directly driving plate roll; and both clutches disengaged for stoppage. A register control system using two alternate drive trains, with speeds as above, includes normally engaging clutch in the 1 to 1 gear train and means for disengaging that clutch and engaging a clutch in the other gear train for a short duration, and then back to the original gear train. Shown are automatic means, preferably a timer, for controlling this cycle. A roll separation system includes a lever with inking slide assembly connected to a point further from lever pivot than plate roll, and looped chain drive driving the rolls irrespective of position of the lever.

United States Patent [191 Skelding et a1. Feb. 12, 1974 1 PRINTING PRESS [57] ABSTRACT [75] Inventors: Geoffrey Harry skewing Old Printing press improvements useful in flexographic Assignee:

Filed:

Swinford, England; Wilbur G. Tracey, Beverly Farms, Mass.

Gloucester Engineering Co., Inc.,

Gloucester, Mass.

Jan. 17, 1972 Appl. No.: 218,346

U.s. C1 101/248, 74/363, 101/181,

Int. Cl B4lf 13/24, B41f 5/16, Fl6h 3/10 Field of Search... 101/180, 181, 183, 184, 248;

' References Cited UNITED STATES PATENTS Brackett 74/368 X Huck 101/248 Renker et a1. 74/368 Slavic 101/180 X Huck 101/181 Lindemann.... 101/183 Giuiuzza 101/183 Slavic 101/181 X Novick 226/30 printing. A register control device comprises first and second freely rotatable gears, separate clutches alternatively securing one or other of the gears to a drive and a bridging shaft having gears meshed with both free gears..With clutch associated with first free gear engaged, drive train from first gear to driven roll results, alternatively with that clutch disengaged and other engaged, drive train from second free gear, through bridge shaft to first free gear to driven roll results. One gear train produces 1 to 1 surface speed ratio between plate and impression rolls, the other produces a register correction speed, off e.g. by 0.5 percent. Also shown are drive shaft directly driving the impression roll with free gears coaxial and free thereon; first free gear directly driving plate roll; and both clutches disengaged for stoppage. A register control system using two alternate drive trains, with speeds as above, includes normally engaging clutch in the 1 to 1 gear train and means for disengaging that clutch and engaging a clutch in the other gear train for a short duration, and then back to the original gear train. Shown are automatic means, preferably a timer, for controlling this cycle. A roll separation system includes a lever with inking slide assembly connected to a point further from lever pivot than plate roll, and looped chain drive drivingthe rolls irrespective of position of the lever.

4 Claims, 5 Drawing Figures PATENTED FEB 1 2 I974 SHEET 1 BF 3 FIG.

PATENTED 1 3.791 ,29@

sum 2 or 3 FIG.

PATENTEU 1 2W4 3 791 294 sum 3 or 3 PRINTING PRESS BACKGROUND OF THE INVENTION This invention relates to printing presses.

In the operation of on-line printing presses (that is to say, presses printing a product as it is manufactured) it is occasionally necessary or desirable to discontinue the printing operation for a period of time. In such processes it is often impractical to interrupt the web production and desirable to have the web continue to pass through the press at its usual pace but without being printed. When the printing is done in a plurality of colors it is also necessary to ensure register between the printings in the different colors. The objects of this invention accordingly include prividing improved, effective and convenient means for discontinuing printing of a printing head while continuing to pass web through the press, for controlling the flow of ink to the printing plated during such discontinuance, for maintaining the register of the printing plate with the web during such discontinuance, and for adjusting a faulty register.

SUMMARY OF THE INVENTION The invention features in a printing press comprising an impression roll, a plate roll, a drive and register system, including a drive shaft, a pair of gear trains connectable to said plate roll, and a respective pair of clutches, means for operating the clutches simultaneously in opposite modes thereby to alternately engage and disengage the clutches and the respective gear trains to the drive shaft, one of the gear trains constructed to drive the plate roll at the speed of its respective impression roll, the second gear train constructed to drive the plate roll at an incrementally different register correction speed, means normally energizing the first clutch, and means responsive to a register correction control for de-engerizing the first clutch and energizing the second clutch, whereby the plate roll can be driven for a short duration at an adjusted speed to correct the phase of the plate roll.

Another aspect of the invention features a lever providing for concurrent withdrawal of the print roll from the impression roll and a screen roll from the print roll in combination with a looped drive chain driving an inking assembly, the drive chain having a first path portion extending from a base to said assembly which increases in length during a movement of the lever and a second path portion extending from the base to the assembly which compensatingly shortens during the movement to maintain driving of the assembly irrespective of the position of the lever.

A preferred embodiment features register means including a drive shaft comprising a dependently driven component of a drive train, first and second gears freely rotatable relative to the shaft and to each other, first and second clutches, one associated with each gear, each clutch having a pair of separable and engageable surfaces, one secured to rotate dependently with said shaft and the other secured to rotate with its respective gear, a bridging shaft carrying a pair of gears secured thereto for dependent movement, one meshed with each of said first and second gears, one of said first and second gears meshed with a driven gear for said plate roll, the register means thereby defining two gear trains, one extending from the shaft through the first BRIEF DESCRIPTION OF TI-IEDRAWING FIG. 1 shows a printing press according to the invention as it might be used to print a continuously manufactured web;

FIG. 2 shows a view of a portion of a printing head of the press shown in FIG. 1;

FIG. 3 shows a view along section 33 of FIG. 2 revealing details of the press particularly germane to the invention;

FIG. 4 shows a detailed view of a portion of the press shown in FIG. 1; and,

FIG. 5 shows a portion of the press of FIG. I viewed from the side opposite to that shown in FIG. 2.

DESCRIPTION OF PREFERRED EMBODIMENT In FIG. 1 is shown a printing press 10, according to the invention. Web 12, which is continuously manufactured in apparatus 14, passes through press 10 and onto further processing in apparatus 16. Press 10 includes four printing heads 18, 20, 22 and 23 each printing a distinct color.

Printing head 22 is representative of all the heads and, as shown particularly in FIG. 2, includes impression roll 24, removable plate roll 26, and inking assembly 28 which includes screen roll 30, ink roll 32, and ink fountain 34. Web 12 passes between impression roll 24 and plate roll 26. Printing head drive shaft 38 is affixed to impression roll 24 and supported for rotation in base 42. Power transmission shaft 36, which is coordinated with the web production rate and the operation of other heads, drives the printing head drive shaft 38 through meshed bevel gears 40. Plate roll 26 carrying plate 27 is affixed to shaft 44, which is supported for rotation on sub-base 46, which is supported on ways 48 of base 42 permitting sliding motion in direction of double arrow 47 between sub-base 46 and base 42. Screen roll 30 with attached gear 31 and ink roll 32 with attached gear 33 are supported for rotation in block 50, which is supported on ways 52 of sub-base 46 permitting sliding motion between block 50 and subbase 46 in the direction indicated by double arrow 49. Disengagement lever 54 is attached to base 42 trhough pivot 56. Threaded push rod 58 is connected to block 50 at pivot 60 and to lever 54 at pivot 62. Threaded push rod 64 is connected to sub-base 46 at pivot 66 and to lever 54 at pivot 68. Screwing the push rods through their pivots permits accommodation to plate rolls of different diameter. Pneumatic cylinder 70 is affixed to base 42 and has actuation rod 72 connected to lever 54 at pivot 74. Stop rod 76 is affixed to base 42 and passes through lever 54. Stop nuts 78 and 80 on stop rod 76 limit the motion of lever 54. Structure corresponding to base 42, sub-base 46, block 50, lever 54, push rods 58 and 64, pneumatic cylinder 70, and stop rod 76 is essentially repeated at the other side of the rolls, where corresponding but primed numerals are given to corresponding parts. Helical gear 82, with pitch diameter equal to the diameter of roll 26, is keyed to shaft 44 so that it turns with the shaft but may be moved along the shaft in the axial direction. Register vernier adjustment mechanism 84 effects such axial motion of gear 82.

As shown more particularly in FIG. 4, adjustment mechanism 84 includes beams 110 pivoted on bracket 111 and with forkedends 112 engaging split ring 114 around gear hub 116. Lead screw 118 is threaded through lead block 120, which is pivoted in ends of beams 110, and is rotationally secured in bracket 111.

As shown more particularly in FIG. 3, wide face helical gear 86, with pitch diameter equal to the diameter I of roll 24, is fitted for free rotation on shaft 38. Pneumatically actuated clutch 88 has face plate 90 keyed to shaft 38 and face plate 92 affixed to gear 86. Gear 94 with pitch diameter incrementally different than gear 86 (Le, larger in preferred embodiment) is also fitted for free rotation on shaft 38. Pneumatically actuated clutch 96 has plate 98 keyed to shaft 38 and plate 100 affixed to gear 94. Gear 102 and slightly smaller gear 104 are affixed to bridging shaft 106, which is supported for free rotation in base 42. Gears 102 and 104 respectively engage gears 86 and 94.

As shown more particularly in FIG. 5, driver chain 122 is engaged around driver sprocket 124 attached to shaft 38 and idler sprockets 126, 128 and 130 journaled on base 42. Drive chain 132 is engaged around sprocket 134 rigidly attached to sprocket 128, sprocket 136 journaled on base 42, sprockets 138 and 142 journaled on block 50, and sprocket 140 attached to screen roll 30. Sprockets 134, 136 and 140 lie within, while sprockets 138 and 142 lie outside the loop of chain 132.

Pneumatic controller 150 receives pressurized air from a source not shown and supplies controlled pneumatic power to operate clutches 88 and 96, and cylinders 70 and 70 through conduits 152, 154, 156 and 158, respectively. In its normal position controller 150 acts to engage clutch 88 and disengage clutch 96. Spring return control button 162 on controller 150, when and so long as it is pressed, effects the disengagement of clutch 88 and the engagement of clutch 96, e.g., for coarse adjustment. Control button 164 is interconnected with a timer so that when it is pressed it initiates a sequence in which clutch 88 is disengaged and clutch 96 is engaged for a definite interval, e.g. during fine adjustment (1 sec. in the preferred embodiment) after which the clutches are returned to their normal states. Control button 165 effects the disengagement of both clutches for convenient removal of roll 26. Controller 150 also includes a control button 160 actuating cylinders 70 and 70' concurrently. The control valving in controller 150 is conventional and well known and needs no further explanation here.

In operation, power shaft 36 rotates shaft 38 and attached roll 24 in coordination with the web manufacture and other printing heads of the press. Web 12 passes through the press in contact with roll 24 at a speed typically I50 ft. per minute.

In the normal printing mode of operation rod 72 is extended so that sub-base 46 is positioned at the left of its range (as viewed in FIG. 2) with the teeth of gear 82 fully engaged with the teeth of gear 86, and with roll 26 making contact with the web. Similarly, block 50 is towards the left so that screen roll 30 is in contact with plate roll 26 and supplies ink thereto. Face plates 90 and 92 are engaged by the action of clutch 88 so that gear 86 rotates integrally with shaft 38. Face plates 98 and 100 are disengaged so that gear 94 rotates on shaft 38, driven by gear 86 acting through gear 102, bridging shaft 106, and gear 104. Because each of gears 82 and 86 has a pitch diameter equal to its associated roll, impression roll 24 and plate roll 26 move with matched surface speeds equal to the web speed.

If, now, an operator desires to adjust the register of one of the printing heads relative to another by advancing the phase of head 22, he depresses control button 162, which, acting through controller 150 causes plates and 92 of clutch 88 to disengage while plates 98 and of clutch 96 are caused to engage. Gear 94 now rotates integrally with shaft 38 and acting through gear 104 bridging shaft 106, and gear 102, rotates gear 86. Because the pitch diameter of gear 94 is slightly larger than that of gear 86, the rotation rate of gear 86 will be slightly greater than the rotation rate of shaft 38, with a corresponding increase in the rotation rate of roll 26 which is driven thereby. The phase of printing roll 26 therefore advances steadily in relationship to the web and the other printing heads as long as the operator continues to depress button 162. In the preferred embodiment the relative advance of the surface of plate roll 26 is 9 in. per minute, equal to 0.5 percent of its normal speed. Alternatively, the operator may effect a discrete advance of the phase of roll 26 by depressing button 164 which switches the gear train into its advancing mode as described above for a definite interval 1 sec. in preferred embodiment) and then returns it to the normal mode. the

It may be noted that designing the gear train to increase the speed of roll 26 driving adjustment (rather than decrease it) has the advantage of facilitating corrections of misalignment due to momentary interruptions in he operation of the printing head.

A vernier adjustment of register may be made using adjustment mechanism 84 to slide gear 82 axially along shaft 44. This movement of gear 82 while engaged through helical teeth with wider faced gear 86 produces a slight rotation of gear 82 and roll 26 in addition to rotation caused by the rotation of gear 86.

If for some reason it is desired to interrupt printing on the web, pneumatic cylinder 70 may be actuated through controller .150 to retract rod 72. Sub-base 46 and block 50 are thereupon moved to the right through the action of lever 54 and push rods 58 and 64, the motion of base 50 being greater because it is connected to lever 54 at a greater distance from pivot 56. Roll 26 is thus moved out of contact with web 12 and inking assembly 28 is moved out of contact with roll 26, thereby interrupting the flow of ink thereto. (It is of course to be understood that corresponding action takes place on the opposite side of the press.) The motion of sub-base 46 is limited by stop nuts 78 acting on lever 54 so that the tips of the teeth of gears 82 and 86 continue to be engaged. Gear 86 therefore continues to drive gear 82 and the phase relationship of roll 26 with the web and other printing heads is maintained. The driving of screen roll 30 through chain 132 is maintained as block 50 slides in direction indicated by double arrow 49 since the change in length of chain between sprockets 136 and 138 is compensated by an equal and opposite change in chain length between sprockets 134 and 142.

What is claimed is: v

1. In a printing press comprising a plurality of printing heads through which a web path extends, each head comprising an impression roll, a plate roll, an inking ment wherein said register means includes drive shafting comprising a dependently driven component of said 7 drive means, first and second gears, said gears freely rotatable relative to said shafting and to each other, first and second clutches, one associated with each gear, each clutch having a pair 'of separable and engageable surfaces, one secured to rotate dependently with said shafting and the other secured to rotate with its respective gear, bridging shafting carrying a pair of gears secured thereto for dependent movement, one meshed with each of said first and second gears, said first gear connected to drive said plate roll, said register means thereby defining two gear trains, one extending from said drive shafting through said first clutch and gear to said plate roll, the other extending from said drive shafting through said second clutch, said second gear and through said bridging shafting to said first gear thence to said plate roll, a first of said gear trains constucted to drive said plate roll at the speed of its respective impression roll, the second of said gear trains constructed to drive said plate roll at an incrementally different register correction speed, means normally engaging the clutch of said first gear train and means responsive to an impression correction control for disengaging said clutch and engaging the clutch of said second gear train, whereby said plate roll can be driven for a shortduration at an incrementally different speed to correct the phase of said plate roll.

2. The printing press of claim 1 wherein said drive shafting comprises a shaft connected directly to drive the respective impression roll and said first and second gears are mounted coaxially upon said shaft, freely rotatable with respect thereto.

3. The printing press of claim 1 wherein said first gear directly drives said plate roll, a gear mounted directly on a shaft extending from said plate roll being engaged with said first gear.

4. The printing press of claim 1 including means to disengage both clutches permitting stoppage of said plate roll. 

1. In a printing press comprising a plurality of printing heads through which a web path extends, each head comprising an impression roll, a plate roll, an inking means, a drive means dependently driving the impression and plate rolls of the heads, and register means for adjusting register of the rotary phase of at least one of said plate rolls relative to the plate roll of another said head whereby register can be maintained, the improvement wherein said register means includes drive shafting comprising a dependently driven component of said drive means, first and second gears, said gears freely rotatable relative to said shafting and to each other, first and second clutches, one associated with each gear, each clutch having a pair of separable and engageable surfaces, one secured to rotate dependently with said shafting and the other secured to rotate with its respective gear, bridging shafting carrying a pair of gears secured thereto for dependent movement, one meshed with each of said first and second gears, said first gear connected to drive said plate roll, said register means thereby defining two gear trains, one extending from said drive shafting through said first clutch and gear to said plate roll, the other extending from said drive shafting through said second clutch, said second gear and through said bridging shafting to said first gear thence to said plate roll, a first of said gear trains constucted to drive said plate roll at the speed of its respective impression roll, the second of said gear trains constructed to drive said plate roll at an incrementally different register correction speed, means normally engaging the clutch of said first gear train and means responsive to an impression correction control for disengaging said clutch and engaging the clutch of said second gear train, whereby said plate roll can be driven for a short duration at an incrementally different speed to correct the phase of said plate roll.
 2. The printing press of claim 1 wherein said drive shafting comprises a shaft connected directly to drive the respective impression roll and said first and second gears are mounted coaxially upon said shaft, freely rotatable with respect thereto.
 3. The printing press of claim 1 wherein said first gear directly drives said plate roll, a gear mounted directly on a shaft extending from said plate roll being engaged with said first gear.
 4. The printing press of claim 1 including means to disengage both clutches permitting stoppage of said plate roll. 